ric@hpspdra.HP.COM (Ric Peregrino) (07/03/90)
I have ported a wave editor program to the amiga and found that the
default stack of 4000 is too small. I tried using a system call in
the program to automatically set the stack, but it seems to fail.
Anybody know why this is, or how it can be done?
#include <stdio.h>
#include <stdlib.h>
void main(void) {
printf("setting stack to 8192\n");
system("stack 8192");
system("stack");
}
the second call to stack with no argument returns the current stack
size: 4000.
Thanks for any help,
ric@hpspdkevin@cbmvax.commodore.com (Kevin Klop) (07/03/90)
In article <13580002@hpspdra.HP.COM> ric@hpspdra.HP.COM (Ric Peregrino) writes: >I have ported a wave editor program to the amiga and found that the >default stack of 4000 is too small. I tried using a system call in >the program to automatically set the stack, but it seems to fail. >Anybody know why this is, or how it can be done? > >#include <stdio.h> >#include <stdlib.h> > >void main(void) { > >printf("setting stack to 8192\n"); >system("stack 8192"); >system("stack"); >} > >the second call to stack with no argument returns the current stack >size: 4000. > >Thanks for any help, >ric@hpspd the ``stack'' command basically means: set the stack size for this process and all children processes to x. the system() call means: start a new process and have it execute the following command. Thus, system("stack 8192"); means start a new process, change that process' stack size to 8192, then exit that process. Note that this does NOT affect the stack size of the process ISSUING the system() call. You are pretty much limited to setting the stack size to whatever you wish BEFORE you run the program, OR setting up your own private stack inside the program (basically, allocating a large chunk of memory, pointing A7 at it, and then moving A7 back to its original position before exiting). -- Kevin -- Kevin Klop {uunet|rutgers|amiga}!cbmvax!kevin Commodore-Amiga, Inc. ``Be excellent to each other.'' - Bill and Ted's most excellent adventure Disclaimer: _I_ don't know what I said, much less my employer.
peterk@cbmger.UUCP (Peter Kittel GERMANY) (07/03/90)
In article <13580002@hpspdra.HP.COM> ric@hpspdra.HP.COM (Ric Peregrino) writes: >I have ported a wave editor program to the amiga and found that the >default stack of 4000 is too small. I tried using a system call in >the program to automatically set the stack, but it seems to fail. >Anybody know why this is, or how it can be done? > >#include <stdio.h> >#include <stdlib.h> > >void main(void) { > >printf("setting stack to 8192\n"); >system("stack 8192"); >system("stack"); >} > >the second call to stack with no argument returns the current stack >size: 4000. Sorry, I only can tell you why this failed (ran into similar things myself): Invoking system makes up a new CLI for this very command and there the stack size is in fact increased. But then this one is closed and the effect is gone before the next statement (that opens a CLI for itself again). The solution I use for similar situations is to start applications only through script files (plus icon and IconX for convenience) that contain only two lines: newcli con:... from file.s endcli (or newshell), where file.s contains the stack command and the call for your application. This way you have _two_ additional windows on the screen at least for short time, but that's not so bad (you can give them identical dimensions and positions, so you hardly notice). -- Best regards, Dr. Peter Kittel // E-Mail to Commodore Frankfurt, Germany \X/ rutgers!cbmvax!cbmger!peterk
nfs1675@dsacg3.dsac.dla.mil ( Michael S Figg) (07/04/90)
In article <13580002@hpspdra.HP.COM>, ric@hpspdra.HP.COM (Ric Peregrino) writes: > I have ported a wave editor program to the amiga and found that the > default stack of 4000 is too small. I tried using a system call in > the program to automatically set the stack, but it seems to fail. > Anybody know why this is, or how it can be done? > > printf("setting stack to 8192\n"); > system("stack 8192"); > system("stack"); > > ric@hpspd My experience is alittle limited but I've been studying this lately. I believe that 'stack' only sets the stack for the current process and each of your 'system' calls is a seperate process besides your program itself. You could set it first from the shell or have a script driving your wave editor which would set the stack first. The stack is only memory for your program to use so you should also be able to do a 'malloc' but I'm not sure how you would allocate this just for the stack. Am I making any sense here? Could someone explain this better so I understand it also! ---Mike -- A man said to the Universe "Sir, I exist!" | Michael Figg DSAC-FSD "However," replied the Universe, | DLA Systems Automation Center "The fact has not created in me a | Columbus, Ohio sense of obligation."- Stephen Crane | mfigg@dsac.dla.mil CIS: 73777,360
jbickers@templar.actrix.co.nz (John Bickers) (07/04/90)
Quoted from - peterk@cbmger.UUCP (Peter Kittel GERMANY): > In article <13580002@hpspdra.HP.COM> ric@hpspdra.HP.COM (Ric Peregrino) writes: > >I have ported a wave editor program to the amiga and found that the > >default stack of 4000 is too small. I tried using a system call in > >the program to automatically set the stack, but it seems to fail. > >Anybody know why this is, or how it can be done? [...] > Sorry, I only can tell you why this failed (ran into similar things > myself): Invoking system makes up a new CLI for this very command and One Bryce Nesbitt wrote some code a while back to do this sort of thing. The stack size can be found by examining your task structure. So one possible way to treat this is to detect that the stack is too small, and error out, with something like: "Sorry bud(ette), your stack is too small." Or you can reset your stack yourself. He wrote a little function to do this, that I have adjusted a little to work with Lattice C and keep stack checking. Hm. Decisions decisions. 127 lines. What the heck... -------------------- 8< -------------------- ;************************************************************************** ;*** stkset.a (JJB TEMPLAR) *** ;*** Date begun: 3/7/89. *** ;*** Last modified: 3/7/89. *** ;************************************************************************** ;*** This module is cut directly from AmigaLine7 (Bryce Nesbitt). See *** ;*** his documentation below for particulars. However, I have added *** ;*** some code to also 'tickle' the __base value used by Lattice stack *** ;*** checking. *** ;*** Problem: should allocation of the new stack memory be done here *** ;*** instead of in the caller? *** ;************************************************************************** LATTICE EQU 1 ; Comment out if don't want __base involved ;--------------------------------------------------------------------------- ;NAME ; SetStack -- use a different process stack ; V1.0 Tuesday 19-Jan-88 04:14:15 By Bryce Nesbitt ; ;SYNOPSIS ; SetStack(newstack,size) ; a1 d0 ; ; char *newstack; ; long size; ; ;FUNCTION ; This function points the current process' stack to a new memory ; location. The active part of the old stack is duplicated, so no ; context is lost. SetStack() also tickles the proper fields in the task ; structure to tell the system about the change. At this time it does ; not deallocate the old stack. ; ;USAGE ; Typically this is used by a process that needs a larger stack than it ; might have been started with. The stack size can be found with: ; ; #include "libraries/dosextens.h" ; ... ; stack=*(ULONG *)( ((struct Process *)FindTask(0L))->pr_ReturnAddr ); ; ; Or in English, the long word at the address pointed to by pr_ReturnAddr. ; ;WARNINGS ; A future revision of exec may do stack blowout checking every time a ; process/task is switched out. This protective feature will not be ; available to programs that use funky methods of swapping stacks. ; ; This only works for processes, tasks are not eligible. ; ; Don't skimp on stack... you'll get burned. Any call to the dos.library, ; for example, takes just under 1600 bytes *minimum*. ; ;INPUTS ; newstack - Pointer to memory block for stack. Must be longword aligned. ; size - The size of the block. Must be an even multiple of 4 bytes. ; ;SEE ALSO ; AddTask() ; ;SetStack() ;V1.0 Tuesday 19-Jan-88 04:14:15 (C)1988 Bryce Nesbitt ;1712 Marin Ave. Berkeley, Ca 94707-2206 415-524-2110 ;ucbvax!hoser!bryce -or- bryce@hoser.berkeley.EDU ; ;Structure of stack: ; ; ------- ; -4 size ; -8 finalRTS ; ... ; -size blowoutdata ;For checking stack blowouts ;************************************************************************** csect text XDEF _SetStack XDEF SetStack IFD LATTICE XREF __base ; offset for stack checking base ; stack is checked with: ; cmpa.l __base(a4),a7 ; bcs.w __xcovf ENDC _SetStack: move.l 4(a7),a1 move.l 8(a7),d0 SetStack: movem.l d2/a2-a4/a6,-(a7) ; Assembler entry (params = reg) ; NOT @function compatible IFD LATTICE move.l a1,__base(a4) ; set __base before a4 used ENDC move.l d0,a0 adda.l a1,a0 ;a1+size=a0 move.l 4,a6 ;exec library move.l $114(a6),a3 ;Internal "magic";FindTask(0L); lea.l $b0(a3),a2 ;&pr_ReturnAddr move.l (a2),a3 ;Get pr_ReturnAddr move.l (a3)+,d1 ;Get old stack size. a3+... move.l a3,d2 ;...now points to old stack top move.l a0,a4 copystack: move.w -(a3),-(a4) cmp.l a3,a7 bne.s copystack move.l d0,-4(a0) ;Set new stack size value move.l d2,a3 sub.l d1,a3 move.l (a3),(a1) ;Copy bottom long addq.b #1,$127(a6) ;Internal "magic" move.l a0,(a2) subq.l #4,(a2) ;pr_ReturnAddr is 4 under top... sub.l a7,d2 ;Get old stack offset sub.l d2,a0 ;index into new stack move.l a0,a7 jsr -$138(a6) ;Public Permit(); movem.l (a7)+,d2/a2-a4/a6 rts END -------------------- 8< -------------------- Assembles ok with Lattice's asm program. > Best regards, Dr. Peter Kittel // E-Mail to Adios. -- *** John Bickers, TAP, NZAmigaUG. jbickers@templar.actrix.co.nz *** *** "Man, Machine -> Super Human Being" - Kraftwerk. ***
jesup@cbmvax.commodore.com (Randell Jesup) (07/05/90)
In article <13580002@hpspdra.HP.COM> ric@hpspdra.HP.COM (Ric Peregrino) writes: >I have ported a wave editor program to the amiga and found that the >default stack of 4000 is too small. I tried using a system call in >the program to automatically set the stack, but it seems to fail. >Anybody know why this is, or how it can be done? Simple. Calls to system() (or Execute()) cause a program to be run on another process. So they set the stacksize for that other process, not yours. Changing your own stack is a bit more complicated. It's pretty easy in assembler, but in C you have to be more careful, especially with exit() and stack-checking. -- Randell Jesup, Keeper of AmigaDos, Commodore Engineering. {uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.cbm.commodore.com BIX: rjesup Common phrase heard at Amiga Devcon '89: "It's in there!"
BAXTER_A@wehi.dn.mu.oz (07/07/90)
In article <13009@cbmvax.commodore.com>, kevin@cbmvax.commodore.com (Kevin Klop) writes: > In article <13580002@hpspdra.HP.COM> ric@hpspdra.HP.COM (Ric Peregrino) writes: >>I have ported a wave editor program to the amiga and found that the >>default stack of 4000 is too small. I tried using a system call in >>the program to automatically set the stack, but it seems to fail. >>Anybody know why this is, or how it can be done? >> >>#include <stdio.h> >>#include <stdlib.h> >> >>void main(void) { >> >>printf("setting stack to 8192\n"); > start a new process and have it execute the following command. > > Thus, system("stack 8192"); means > > start a new process, change that process' stack size to 8192, then > exit that process. > > Note that this does NOT affect the stack size of the process ISSUING the > system() call. Note however that you CAN use the Lattice functio Execute like this: Execute("stack 8192\n programname"); (with the other arguments, which escape my mind at the moment) Regards Alan